Visual Programming w/ Visual BasicHow to prepare your mind to face the endless nightmare

By Williem

To make new project

In main menu, click “New Project”

Choose your destination folder and remember to change your name (for the sake of originality, you’ll see later)

VS Topography

Left Side : Toolbox

Bottom-Right Side : Properties of selected object

Top-Right Side : Solution and Project Mapping/Explorer

Upside Menu Bar

Form to create your interface

The holy green triangle to debug and start your program

Gizmos

Button

Checkbox

Label

Combobox

RadioButton

Textbox

GroupBox

Timer

IMPORTANT!

To change every information regarding to specific objects, go to the Properties. It is essential

How to create the interface

VB consentrates on creating a user interface and manipulating the objects so we can do something better or even create and application

E.g. Create an application that says “Hello World” when a button is clicked

How to:

1. Create a new project

2. From the toolbox, drag the “Button” tool to the Form

3. To change the button’s text, go to Properties and change the “Text” infobox

4. To manipulate the code (sorry to say such holy word), double-click the button in the form*.

5. In the code, under the Private Sub blablabla, type “MsgBox(“Hello World”)”

6. Click the holy green triangle

P.S. : *This applies to every object in later use, just keep in mind

Variables

Almost same as C/C++, variable defining is essential in VB

To define variable use “Dim” keyword

< Dim myVar As Single/Double/Integer/String/Boolean etc. >

Visual Basic is not case sensitive, so A and a are just the same. Be careful.

To comment your program use the apostrophe ( ‘ )

MsgBox

MsgBox (not MonoSodium Glutamate) is essential and can be manipulated

MsgBox([Contents], [Type], [Box Text])

If you want to concatenate string, use “+” or it will be much professional to use “&” because it does for string and numerical *

Types of the textbox determine the style, can be exclamation, yes or no, ok or cancel, ok, etc.

MsgBoxStyle.Information

MsgBoxStyle.Exclamation

And many other stuffs you can explore

*p.s. : because you will encounter some program with direct addition in the box

Textbox To take the value of text input, use “[TextBox_Name].Text”

E.g. Dim myInt As Integer

myInt = Textbox1.Text

Converting is essential in taking input value. The only reason is every input you do in the textbox is taken as String value.

To convert to Integer: myInt = Cint(Textbox1.Text), etc.

Double = CDbl

String = CStr

Single = CSng

A question: What if the input is 12A?

So easy…

Just use “IsNumeric()” function.

IsNumeric([Input])

This function returns Boolean value (True / False)

What does “IsNumeric(Textbox1.Text) = False” ?

Almost all programs in Visual Programming use this function. KEEP IN MIND

The Math Logic or Boolean Algebra

Remember “||” or “&&” ?

In VB, we use “And” or “Or”

|| is Or

&& is And

<> is Not Same As (or ‘!=‘ in C/C++)

! is Not

== and = is different and it is self-explanatory.

RadioButton

To make it checked by default, go to Properties->Checked->True

To use it in code, [RadioButton_Name.Checked]

In default, it is considered true. Example: Male.Checked = False, what does it means?

And it can be combined with logic And / Or to achieve some purposes.

Conditional (If-Else-Elseif) and (Select-Case) Like other languages, the If-else-elseif in VB is just the same, but remember,

you have to be able to separate some if

Always remember, after If – Then, Elseif – Then, Else (no Then) and End If.

*usually auto-typed by VB, but keep your eyes on them unless you want to shout like sh*t when error happens in debugging because of no “End If” or even “Then”

Select is like switch

Select Input

Case 0

Condition….

…(continue)

End Select

Loops (While, Do While, For)

While and Do While is like in C/C++ except for While, it has End While

Do … Loop While/Until.

Or Do While (Condition) … Loop . It is self-explanatory or not clear enough?

For … To … (Step -a)

Next

Step is used to determine the difference in every loop, can be negative or positive

Bonus Sneak-Peek (Array)

Usually used to manipulate string.

To take string length just use myStr.Length as in C/C++

Dim myStr As String

myStr = Textbox1.Text

‘Assume input is Hello

MsgBox(“The character is” & myStr(2))

….

What is the result?

Challenge 101

Create a program that counts temperature from:

Fahrenheit to Celcius and vice versa

Celcius to Reamur and vice versa

Reamur to Fahrenheit and vice versa

All to Kelvin and vice versa

And Show the conversion result

Use one textbox, one button and 8 radiobutton

Create a program that reads String input from textbox and Reverse it manually with loop by clicking a button (any loop will do), then show the result!

Use one-dimensional array! (there are two ways to do it )